Dover Corporation Interview Question

class template vs template class? c++ specific properties? struct vs class? encapsulation vs abstraction? Design a holder - bulbs(LED,Normal,Tube light) - uml relation ship? multiple inheritance, multiple level inheritance-CTOR and DTOR order for base classes ? why use templates? what is abstract class? unit testing tools used? smart poiner vs dangling pointer why we take "Base& obj" as input in Base Copy CTOR function, in Base(Base& obj){}, why not "Base obj". shallow copy vs Deep copy.